My First Attempt UV (BG39 + WB2) some portraits and buildings - Any CC Appreciated!

[dabateman]

I have a Tangsinuo bg39 filter that has a minor 650nmish peak.  Its enough to cause problems with a zwb2 filter. Even worse with a zwb1 filter. It does create some beautiful red IR with the right filter. 

You may have a similar red leakage. 

[mason2spectral]

 

 

 

4 hours ago, Andy Perrin said:

Ok, here is what I get from a quick test using BG39 2.5mm and UG11 2mm on (full spectrum) Sony A7S. The top row is the Sony 55mm/1.8 and the bottom is the Kuri 35/3.5 (which is known to have good UV pass). For the left side I took a photo using normal settings (whatever looked nice, this is just so you can see the colors), and for the right photo I used the same F/5.6 1/100" ISO3200 that was used by mason2spectral. As I expected, at 1/100" the image is very dark in both cases. The Sony clearly is transmitting much less UV than the Kuri, as we would expect.

 

All white balances were done off of PTFE in PhotoNinja on the computer (not in-camera).

 

The grass is dark and the sky is light, which is normal for UV pictures. The Sony has much less color and obviously a much-reduced bandpass. I also noticed that the Sony did not like to focus well in UV.

 

 

Definitely very different from my results. I may be seeing some UV though as the windows in some of my shots look similar but maybe i'm just being hopeful ;)

 

3 hours ago, Andy Perrin said:

The best for IR cutting for UV photography (not visible) is S8612 2mm. If you get some of that, you are pretty much set for life. The BG glasses are all inferior to S8612, and knockoffs may be even worse.

3 hours ago, Yves W said:

I have different models of BG39=QB39. I have Tangsinuo and I'm not sure they're the best for IR cutting.

I am looking for others that I have already purchased but whose contact details I have lost.

1 hour ago, dabateman said:

I have a Tangsinuo bg39 filter that has a minor 650nmish peak.  Its enough to cause problems with a zwb2 filter. Even worse with a zwb1 filter. It does create some beautiful red IR with the right filter. 

You may have a similar red leakage. 

 

@dabateman Here is what my non-white balance raw looked like:

 

Is it possible to stack on a Kolari Vision Hot-mirror Gen1 for now? Will UV still get through or will it cut too much?

 

The ZWB2 seems to have had bad threading on the filter ring as it seems to now be bound permanently to the BG39 -- I can't get the two apart and sliced my fingers in the process of trying. I ended up filing a dispute on aliexpress. 

 

Is there an easy solution to this? Any recommended filter combinations or filters that would work better? As a student, I am on a relatively tight budget. I originally got these filters in 72mm as all my step ups are for 72 and most of my existing Sony lenses have larger sized filter requirements -- which would makes options such as the Kolari UV filter way too expensive.

[Andy Perrin]

You need to block the IR much better, which means thicker BG39 or a different filter. Stacking on the Kolari Gen 1 Hot mirror might help.

 

Also OUCH on the 72mm. I think you should shoot for 52mm filters for your UV setups. Most of your existing Sony lenses are no good for UV anyhow, as I just demonstrated above. UV requires lenses that pass UV well, and can focus UV well, which does not really mesh with the native lens system!

[mason2spectral]

1 hour ago, Andy Perrin said:

You need to block the IR much better, which means thicker BG39 or a different filter. Stacking on the Kolari Gen 1 Hot mirror might help.

 

Also OUCH on the 72mm. I think you should shoot for 52mm filters for your UV setups. Most of your existing Sony lenses are no good for UV anyhow, as I just demonstrated above. UV requires lenses that pass UV well, and can focus UV well, which does not really mesh with the native lens system!

It was already getting dark out by the time I was able to go out. I did take some comparative images with/without hotmirror stacked on top. Will upload them in a bit.

[mason2spectral]

1 hour ago, mason2spectral said:

It was already getting dark out by the time I was able to go out. I did take some comparative images with/without hotmirror stacked on top. Will upload them in a bit.

The shots definitely show that the ir cut filter + zbw2 has some sort of leakage. Everything was shot on the 55 f1.8

 

Indoor light strip without kolari hot mirror on top (f1.8, 1/13 sec, iso 25600):

Indoor light strip with kolari hot mirror on top (f1.8, 1/13 sec, iso 25600):

 

Outdoor street light without/with kolari hot mirror on top (f1.8, 1/40 sec, iso 25600):

notice some light leaks out of the top of the street light with only the ir-cut

    

 

 

Similar to the photo I took in the original post here but with kolari hotmirror added on top (bw & color: f1.8, 1/40, 25600)

 

Long exposure with kolari hotmirror on top (daylight was pretty much fading at this point -- f/2.8, 0.8s, 6400):

   

Long exposure with only ir cut (daylight was pretty much fading at this point -- f/2.8, 0.8s, 6400):

 

@Andy Perrin @nfoto @dabateman

 

Are the results with the zbw2 + BG39 + Kolari Hotmirror Gen1 better? My worry is adding the hotmirror may be cutting the UV light or causing a shift in the images... It does seem to make a difference though.

[Andy Perrin]

Yes, the hot mirror is helping a lot. The ones with the hot mirror look mostly or all UV. You aren't getting much color in your image because your LENS is still blocking most of the UV, and you haven't white balanced. The hot mirror is probably not losing you much UV. Keep it on there. 

 

Finally, when you white balance, make sure not to use Adobe products because they are incapable of white balancing UV images. PhotoNinja, Capture One, Darktable, and some others are all able to do a UV white balance. Darktable is free.

[mason2spectral]

52 minutes ago, Andy Perrin said:

Yes, the hot mirror is helping a lot. The ones with the hot mirror look mostly or all UV. You aren't getting much color in your image because your LENS is still blocking most of the UV, and you haven't white balanced. The hot mirror is probably not losing you much UV. Keep it on there. 

 

Finally, when you white balance, make sure not to use Adobe products because they are incapable of white balancing UV images. PhotoNinja, Capture One, Darktable, and some others are all able to do a UV white balance. Darktable is free.

I used to have an older version of photolab and I swear it accepted ir color balancing properly -- photolab 5 seems to not do so anymore. Is there a recommended guide of any kind to create a DCP for lightroom? 

 

Oddly the long exposure water photos, the water looked oddly similar with the ir leakage and without. Maybe the leakage was quite low and not totally able to overpower the UV light? Could shooting at dusk have something to do with it?

[Andy Perrin]

Lightroom cannot be used. The sliders won't go far enough. 

 

Water tends to look darker in IR and lighter in UV, but aside from that I wouldn't expect much change since it's mostly just reflecting surroundings.

[dabateman]

Dusk has low UV levels. 

These with the hot mirror look more UV like.

I also own dxo photolab 5, but haven't had the time to play with it since I bought it in December. Photoninja has been the easiest for white balance. But Art, a fork of RawTherapee also can work. RawTherapee hasn't been updated in 2 years,  whereas Art seems current and can do some selective editing. 

[Nate]

5 hours ago, mason2spectral said:

Is it possible to stack on a Kolari Vision Hot-mirror Gen1 for now

I have that one in the 37mm size, and my version 1 does not go that low, wishing it would have. I'll need to try it again with the diffraction grating, but if I remember right, it maybe went down to 370nm.

[Nate]

5 hours ago, mason2spectral said:

I can't get the two apart

I use two strips of duct tape on each filter, and pull in opposite directions, left hand away from me, right hand toward me. I find I need to do this more times than I should.

[Andy Perrin]

Nate, the Sony lens he’s using probably doesn’t go below 370nm either, so for now it’s ok. At least the photos look UV, and it’s fine for monochrome. 

[mason2spectral]

1 hour ago, Nate said:

I have that one in the 37mm size, and my version 1 does not go that low, wishing it would have. I'll need to try it again with the diffraction grating, but if I remember right, it maybe went down to 370nm.

What is diffraction grating? 

[Andy Perrin]

12 minutes ago, mason2spectral said:

What is diffraction grating? 

A piece of glass or plastic with very closely spaced grooves in it that can split light into separate wavelengths like a prism, except it's flat. They are handy and also cheap! Nate was using his to see roughly how low the lenses went relative to each other.

[Nate]

@mason2spectral These are the ones I bought https://www.amazon.com/gp/product/B00K6K3MCW/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

 

These gratings are great for getting an idea what passes and what's blocked. I just tested a new asto filter(Hydrogen-A 12nm) that I got today

 

This is one of the topics using them, If you can get a small enough slit from the light source, you can see the Fraunhofer lines.

 

 

[mason2spectral]

37 minutes ago, Andy Perrin said:

Nate, the Sony lens he’s using probably doesn’t go below 370nm either, so for now it’s ok. At least the photos look UV, and it’s fine for monochrome. 

In that case any inexpensive lens recommendations that would adapt well on FE mount?

 

Preferably ones that also work well in IR...

[Andy Perrin]

Yeah, the EL-Nikkor 80mm/5.6 (with metal rim - they come in metal and plastic) is the classic "good first lens". 

https://www.ultravioletphotography.com/content/index.php?/topic/4280-nikon-80mm-f56-el-nikkor-nippon-kogaku-japan/#comment-41477

 

It needs a helicoid and adaptor ring (which can be bought from RafCamera on eBay) to focus and attach the filter.

 

It's a wicked sharp lens, probably one of the sharpest ones I own. And yes, it works fine in IR.

[Nate]

Here's how I mounted my EL Nikkor 80(metal) @mason2spectral Your helicoid will probably vary from mine because of different flange distance to sensor.

[Andy Perrin]

It's also fantastic for macro work if you add some extension tubes or a longer helicoid. It's probably my most-used lens!

[mason2spectral]

17 minutes ago, Nate said:

Here's how I mounted my EL Nikkor 80(metal) @mason2spectral Your helicoid will probably vary from mine because of different flange distance to sensor.

Looks pretty complex! Also noticed you strapped a torch to the top. Is it that useful? I tried to find the Nemo torch mentioned in the forum but couldn't seem to find it  

[Andy Perrin]

Yeah, i don’t see the original Nemo at the moment. But I think someone here had bought this version and it was okay?

 

https://www.ebay.com/itm/Alonefire-SV13-15W-365nm-UV-Flashlight-USB-Rechargeable-Ultraviolet-Blacklight-/284210697930?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=711-127632-2357-0

 

“Nemo” just means “no name” in Latin anyway…it was my joke because the original was a no-brand-name torch from eBay. 
—

 

Re the lens - get used to working with helicoids, weird step rings, etc. In this hobby it’s rare that we can use anything off the shelf or the way it was originally designed. 

 

UV photographer: a person who takes ultraviolet photos using a camera not designed to see UV, in conjunction with a lens that does not want to transmit UV, with a filter that leaks infrared, using light sources that are mostly visible and IR. 

[ulf]

I searched for "uv flashlight 15w" on eBay

 

Here is one of the Nemos I found:

https://www.ebay.com/itm/403045517412?_trkparms=ispr%3D1&hash=item5dd7628864:g:xPEAAOSwg6hhC7Ze&amdata=enc%3AAQAGAAAA8M6fYutFZu1knfksK5PoGT4dJYLoNq4gNyIuFymAINuuLJzLB8VBmZVqEqOQmH0yS058CsioHKjYp5QHvj4o1GqH1Doddn6Wx9%2F0y1cdvhxGcIKnJ6ru9LKSp5iABrZttBdY3PPrRUsukRnglVaFf%2B2WTlqLEazz3vbnB%2FDgjHdd6DF0bT2CO9jG%2FMVebzAMXHArG1js6zIHJcDQ5zrPJ3HoBUEBq4%2BGyPeq%2B6eD4AHfPKOv9yYYkxCYEEodl776pBzI9zJEKlDqT0%2BNADR39%2B9g0NiDAOU%2F%2BZ0avGvBytHbJBpCIfWTFsqHUDftzoztkg%3D%3D|tkp%3ABFBMvqSZlvtf

 

[Andy Perrin]

Thanks Ulf, I thought we would have to make a movie called "Finding Nemo"...

[Nate]

46 minutes ago, mason2spectral said:

Looks pretty complex

It looks it, but once you get all the parts, it's pretty simple. That one was my IR setup with a 940nm torch and 850 filter.

Here's what I use for UV, notice the most valuable item, LCD magnifier. The tube adds contrast, because I have a hotspot with my 1.25in filter on the inside.

 

 

[ulf]

@Andy PerrinThanks for the lens comparison.

A third and IMHO better test setup is like the last one with equal stop-down, but then good exposure times without saturation. Then it is easy to compare the differences of the needed exposure that is a rather good indication of the UV-pass differences between lenses for a given filter/camera combination.